Compatibility Policy

Intro
For summary of default compatibility guidelines refer to the
Compatibility Guidelines
The purpose of the compatibility policy is to make promises to the users of Yagna software regarding the compatibility of Yagna packages against their software (a proprietary app referencing a ya*api library may or may not be compatible with subsequent versions of the library) and against each other (Requestor nodes running one version of Yagna may or may not be compatible with Provider nodes running a different version).
Note: the policy must address following concerns:
The Developer of the Requestor agent application is concerned about whether new ya*api editions will still support his application
The operator of a Provider node is concerned about which packages he needs to install in order to target as broad a population of Requestors as possible
IMPORTANT:
For the purposes of this policy we make no distinction between the App Developer and the Requestor. This is in order to simplify the compatibility guidelines, by abstracting from the compatibility dependencies between Agent Application and the components on the Requestor and Provider nodes.
Yagna packages
A Yagna release includes Requestor and Provider packages. Each package contains a set of components required to setup a Requestor or Provider node, respectively.
This policy assumes a number of simplifications, without sacrificing generality:
By Requestor version we consider a bundle of specific versions of following components intended to be running on Requestor node:
yagna daemon
ya*api libraries
This implies we are not considering the compatibility between specific versions of ya*api libraries and different versions of yagna daemon modules.
By Provider version we consider a bundle of specific versions of following components meant to be running on Provider node:
yagna daemon
ya-provider agent application
ExeUnit and runtime modules
This implies we are not considering the compatibility between specific versions of ya-provider application and different versions of yagna daemon and exeunit runtimes.
Versioning scheme
Yagna packages are versioned according to the Semantic Versioning 2.0 (https://semver.org/) - the most significant aspects of it are repeated below for convenience.
The version numbers are assigned using following scheme:
major.minor.patch
Where:
major, minor, patch are incrementing integers
Following rules apply:
For initial development (major version = 0) the compatibility may be broken at anytime. The APIs should not be considered stable.
For versions 1.0+ the rules are:
Major updates imply potentially incompatible changes to existing APIs, components and packages, eg. removal of features, APIs or modules.
Minor updates are related to adding features to existing APIs, preserving backwards compatibility.
Patch updates are reserved for bug fixes, maintaining compatibility.
Compatibility concepts
We consider following compatibility relationships:
Requestor Agent App <-> Requestor package version
By “Agent App is compatible with a specific Requestor package version” we state that Agent App is compatible with a relevant ya*api library version associated with that Requestor version. In other words, having a yagna package 0.6.0, including yapapi version 0.4.1 we say Agent App is compatible with yagna 0.6.0 when this Agent App is dependent on yapapi 0.4.1 and is run against yagna 0.6.0 on Requestor node.
Requestor version <-> Provider version
By “Requestor version A is compatible with Provider version B” we state that:
a Requestor node running version A can interact over the Golem Network with a Provider node running version B in the context of Market, Activity and Payment API interaction
A relevant ya*api library behaviour of version A corresponds with the behaviour of ya-provider Agent and ExeUnits/runtimes of version B.
Backward compatibility
Wherever possible, the APIs will be maintained in a backwards compatible manner. If it is necessary to change an API in a way that is not backwards compatible, a new API shall be created, and the old API will be maintained in accordance with the deprecation policy.
The behaviour of an API may change in case of bug or vulnerability fixes.
Compatibility matrix
A matrix indicating the compatibility between Requestor and Provider versions shall be maintained (indicative example below):
Text
Provider versions
Text
Text
Text
Text
Text
Requestor versions
0.5.0
0.6.0
0.7.0
MVP release
(1.0.0)
Minor release
(tent. 1.1.0)
Next major release
(tent. 2.0.0)
0.5.0
Y
N
N
N
N
N
0.6.0
N
Y
Y
Y
N
N
0.7.0
N
N
Y
N
N
N
MVP release
(1.0.0)
N
N
N
Y
Y
N
Minor release
(tent. 1.1.0)
N
N
N
Y
Y
Y
Next major release
(tent. 2.0.0)
N
N
N
N
N
Y
Notes:
While in Alpha mode, Yagna packages are likely to break backwards compatibility from release to release
Once in Prod mode, major updates of Yagna Provider packages should maintain backwards compatibility up to 2 minor releases of Requestor packages
The Provider packages are not consciously forward compatible (ie. Provider will fall out of interest when running outdated versions)
IMPORTANT:
The rules above imply a generic guideline for the Providers: by default upgrade to the latest Provider package version available, as that version will still support non-latest Requestors, and therefore provide widest market coverage.
Deprecation policy
The behavior of an API or a component must not change between any two consecutive releases unless it is going through the deprecation process as described below:
An API or component cannot be removed without notice between any two consecutive releases
When a breaking change is required, the following process will be observed:
Major release N:
New methods, parameters or components to support the new functionality can be added as long as the old functionality continues to work
Old API is marked as deprecated (in a way relevant to the language-specific deprecation labelling patterns) and still functions properly without breaking
Release notes must include information about incoming breaking changes
Major release N+1:
Remove deprecated items
Make breaking changes
Announce breaking changes and end of deprecation period in release notes
Experimental features
Some features, components or API elements may be explicitly marked as experimental. The purpose of experimental features is to publish new concepts, gather community feedback and allow to stabilize.
Experimental features may change with any release, and the change may include:
Change of behaviour or API specification
Removal of feature, component or API
Promotion to stable status - from that point the default deprecation policy applies.
Release note sample
SUMMARY:
With this release, we are excited to share zkSync L2 Payment Driver support.
(...)
CHANGELOG:
GolemSP:
Support golemsp stop (#787)
Provider:
Reduce timeout for closing agreements when no activity is made from 30 minutes to 90 seconds (#835)
Update provider agent readme (#750)
(...)
DEPRECATED APIs:
[Payment API] GetAccounts method has been marked as deprecated
[yapapi] Runner class has been marked as deprecated and superseded by Executor class.
[...]
API LIBRARY COMPATIBILITY:
Library
Requestor
Provider
yapapi
0.5.0+
0.6.0+
yajsapi
0.5.0+
0.6.0+
...
...
...
By installing & running this software you declare that you have read understood and hereby accept the disclaimer and privacy warning found at https://handbook.golem.network/see-also/terms​
ya*api libraries
Versioning scheme
ya*api libraries are versioned according to the following scheme:
major.minor.patch
Where:
major, minor, micro are incrementing integers
Semantic versioning 2.0 (https://semver.org/) rules apply.
ya*api libraries are labeled with required versions of interfacing packages, eg:
Required dependencies:
1
Yagna \(Requestor\): 0.18.0+
2
​
3
Yagna \(Provider\): 0.17.0+
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Within a major version we guarantee the APIs to be backward compatible, but not forward compatible. Ie. newer releases may add elements to the API, but they should not alter or remove.